Usually refers to people who have professional knowledge and experience in a certain field. They usually establish long-term relationships with students and provide guidance, support and advice to help them develop their careers or personal growth. Trainers are usually professional educators. They design and implement training to help employees acquire specific skills and knowledge to improve their work performance. Teachers are usually educators in schools or universities, teaching subject knowledge and skills and helping students acquire academic achievements and knowledge. Coaches are usually people with professional knowledge and experience in sports or other fields. They organize training courses to help people improve their sports skills and challenge themselves. Generally speaking, these roles help others to develop and succeed, but the main difference lies in their professional knowledge and experience, and the support and guidance they provide.